Nature of Science: Scientific Inquiry, Methods, Techniques, and History

Question 1

Making observations

Answer 1

–quantitative: can be measure, such as number, length, mass, volume

–qualitative: cannot be measured, color, shape, texture

Question 2

Formulating and Testing Hypotheses

Answer 2

–a proposed explanation for natural phenomena

Question 3

Identifying Experimental Variables and Controls

Answer 3

• -experimental variable: can manipulate

- -experimental controls: variables kept constant

Question 4

Conclusions: proof vs support

Answer 4

• -evidence is not known as scientific proof

- -scientific conclusions and evidence are not accepted as final proven knowledge

Question 5

Scientific resources & communicating findings

Answer 5

• -findings: maintain accuracy and clarity

- -properly citing, to build new findings

Question 6

Chemical nature of biology

Answer 6

• -chemistry: study of matter or any physical substance that takes up space or has mass
• -all living things made of matter, all matter made of atoms
• -living organisms made of: C, H, N, O, S, & P
• -biochemistry: study of how these elements combine into biomolecules
• -biomolecules: carbs, proteins, lipids, nucleic acids
• -actions and rxns of the biomolecules drive photosynthesis, cell resp, and digestion

Question 7

Calculations in biology

Answer 7

–mathematical models: simulate natural phenomena and predict their future

–statistics: summarize and draw conclusions about data in biological experiments

–mathematical biology: inspired by complex biological processes

–theoretical biology: uses data from complex models to develop theoretical assessment of biological processes

Question 8

Physical Laws and Principles Governing Biological Systems

Answer 8

• -physical biology: understanding natural processes
• -physics: study of matter, energy, and motion
• -includes laws of motion and thermodynamics, and laws of conservation

biophysics: describe and explain patterns in biological processes

Question 9

Testable nature of hypotheses

Answer 9

• -scientific facts: objective observations not explanations, confirmed by data repeatedly
• -facts accepted as truth, not proof

–hypotheses (proposed and testable) and theories: explanations of natural phenomena

Question 10

Formulation of theories based on accumulated data

Answer 10

• -hypotheses: tested and confirmed time and time again, data accumulated to be considered theory
• -many sources of evidence needed
• -theory: valid explanation of phenomena

Question 11

Durability of laws

Answer 11

• -not explanations of phenomena
• -description of natural phenomena
• -distinguished by their durability
• -durability: ability to stay constant over time and their predictive nature

Question 12

Cell theory and germ theory

Answer 12

Cell theory: all living things are made of cells
–Robert Hooke: used microscope to identify, describe, name cells

Germ theory:

• -Louis Pasteur
• -discovered microorganisms cause food spoilage and disease
• -confirmed cell theory by showing cells come from other cells

Question 13

Heredity, evolution, and ecology

Answer 13

Heredity: how genes pass thru generations

• -Gregor Mendel
• -observed variation in pea plants by cross breeding plants for specific traits
• -concluded plants get one allele from each parent and one of these will be expressed as trait

Evolution: how sp change over time
-Charles Darwin

Identified driving forces

• -descent with modification
• -natural selection

Both heredity and evolution play major role in ecology

Question 14

Structure and nature of genetic material

Answer 14

–genetics: studies structure and fn of genetic material as chromosomes and how passed on

Alfred Hershey and Martha Chase
-confirmed DNA has the genetic material

James Watson and Francis Crick

• DNA is double helix
• Rosalind Franklin contrib data to this discovery

Question 15

Classification of organisms

Answer 15

Biological Classification

• -group organisms based on similarities
• -taxonomy
• -based on hierarchical system by Carl Linnaeus
• -Carl Linnaeus system grouped species
• –Kingdom, Phylum, Class, Order, Family, Genus, Species
• -system modified by Carl Woese
• discovered Archaea
• added Domain

Question 16

Precision vs accuracy

Answer 16

Precision: how close repeated values are to one another

Accuracy: how close measured value is to true value

Question 17

Metric and SI units

Answer 17

• -modern form of metric system
• -helps to maintain standards of data across countries

metric system: use metric units
–prefix paired with base unit

SI units: 
meter (length)
kilogram (mass)
second (time)
ampere (electric current)
kelvin (temp)
candela (luminous intensity)
mole (amt of substance)

Question 18

Unit conversions

Answer 18

–conversion: changing a metric or SI unit into another metric or SI by multiplying or dividing by a power of 10

–conversion factor: power of 10, indicated by name of prefix

–conversion factor is multiplied for converting to a smaller unit
& divided for converting to a larger unit

Question 19

Scientific notation and sig figs

Answer 19

–shorthand method of writing very large or small numbers

sig figs: non-zero numbers, zeros bw them, and final zero

the more sig figs the more precise

Question 20

Linear vs log scales

Answer 20

Linear scale: shows equal values using equal divisions
–explain direct relationships

Logarithmic scale: nonlinear–units written in orders of magnitude or powers of 10
–makes ratio based comparisons for large amts of numbers

Question 21

Identify patterns and trends in data

Answer 21

Patterns

• -tables, graphs, charts to identify
• -used for patterns with similar or repeated sequences of data

Trends

• -data that moves in general direction
• -requires accurate data

Question 22

Choose appropriate types of of graphs or charts

Answer 22

Line graphs & Scatter Plots

• -show relationships bw variables
• -record quantitative data
• -independent variable (x)
• -dependent (y)
• -line graphs :large trends

Bar graphs

• -compare data
• -exist in diff categories esp if qualitative data

Histograms

• -similar in structure to bar graphs
• -represent data that can be expressed in ranges of numbers not categories

Pie charts:

• -represent data when expressed as a proportion of a whole
• -data interpreted in comparison with all data collected

Question 23

Error Analysis

Answer 23

• -systemic errors stem from flaws in data, alters accuracy
• -random errors: unpredictable
• -both types must be accounted for in error analysis

Error Analysis

• -calculates percent error observed in experiment
• -done by comparing results to established value
• -percent error less than 10% is acceptable

Question 24

Draw conclusions and make predictions

Answer 24

–any errors should be incorporated into conclusions

–scientists analyze data from figures to draw conclusions from the trends and make predictions

Question 25

Limitations of models

Answer 25

- -Cannot be exact replicas | - -scientists have to use multiple models and modify existing ones for new observations

Question 26

Select models for a given purpose

Answer 26

--model: description or representation of natural phenomena used to help explain or understand it --diff models for diff purposes

Question 27

Physical, conceptual, graphical and/or mathematical models

Answer 27

Physical: physical copies of phenomenon built to scale -physically visualize processes/phenomena Conceptual: visual representation of abstract concepts while also describing behavior Mathematical: describe and predict behavior or phenomena Graphical: probability and statistics

Question 28

Molarity and percent solutions

Answer 28

Molarity: measure of a solute or dissolved material in a solution --used to express percent concentration of that solution --solutions can be diluted by adding more solvent (the substance in which the solute is dissolved)

Question 29

Acid and base solutions

Answer 29

--Repairing and using these solutions requires additional safety procedures Acids: corrosive, must use aprons, nitrile rubber gloves, chemical splash goggles - -proper ventilation - -eyewash - -spill control materials - -always add acid to water NOT vice versa - -stored in corrosives cabinet Bases: --can be stored same space but physically separated from acids All prepared and stored solutions must be: - -labeled with acid - -concentration - -hazard warning - -date prepared - -review MSDS before disposal - -always dilute and neutralize acids

Question 30

Flammable and/or caustic materials

Answer 30

Flammable/caustic: able to destroy organic material

Question 31

Biological specimens and waste

Answer 31

- -blood, urine, tissue, culture specimens - -use pipettes or leaf proof containers for biohazards - -use disinfectants if are infectious materials - post hazard signs - -materials must be contained, appropriate materials used - -materials stored in biological safety cabinets --biological waste: when dispose must be inactivated by autoclaving or bleach treating within 24 hrs --inactivated and non biological waste and sharps placed in closed leak proof biowaste container

Question 32

Optical Equipment

Answer 32

--disperses, concentrates, redirects light using lenses, mirrors, or prisms --microscopes and telescopes: use objective lenses and eyepiece lenses to magnify --LASERs: high energy, narrow beams of concentrated monochromatic light --Spectrometers: measure/record light properties and wave spectrums

Question 33

Separation Equipment

Answer 33

--separates mixture into distinct separate components Mechanical separation - -filtration using funnels or sieves - -remove large particles from liquid - -centrifuge: separate mixture at high speeds Chemical separation: - -via distillation - -purifies and separates liquids thru heating and cooling - -uses burners, tubing, flasks - -chromatography: separates mixtures by allowing gas or liquid to flow over material - -components separate as they flow at diff rates - -use columns, detectors,, pumps Magnetic separation: - -magnetic devices to attract and remove magnetic components out of the non magnetic substance in mixture - -uses separators and columns Electric Separation: - -gel electrophoresis - -uses electrical pulses to separate DNA, RNA, and/or proteins - -uses power supply, chambers, gel, etc

Question 34

Measurement, mixing, and heating equipment

Answer 34

- -meters sticks - -graduated cylinders - -balances - -thermometers - -timers - -use metric system - -pH: 14 point scale mixing lab equipment: - -pipettes - -stirrers heating lab equipment - -remove all flammable materials - -Should be AVOIDED: plastic, closed or narrow neck containers (flasks) - -crucibles: used for heating things at high temps - -protective clothing and equipment (tongs, hot pads) Open flames: - -alcohol burners: low open flames at low temps - -bunsen burners: higher hotter flames Other heating: - -ovens - -uniformly heat and dry materials

Question 35

Sterilization Equipment

Answer 35

--effectively remove bacteria that could present a hazard Small scale sterilization: --wiping materials with solvent or heating in ovens or over burners Large scale sterilization: - -industrial sterilizers - -autoclaves Autoclaves: high pressure and temp, reliable --121 degrees Celsius for 15-20 minutes, up to 30

Question 36

Use of MSDS or SDS

Answer 36

--chemical cmpds and solutions used in lab must have MSDS or SDS MSDS contains - -potential health, fire, reactivity, and environmental hazards - -instructions for: - proper and safe prep - use, storage, handling - preventative and first aid

Question 37

Use of PPE

Answer 37

- -minimize hazard exposure and reduce risk of injury/illness - -must follow OSHA PPE program must meet: - identify and address potential hazards - -select proper PPE based on hazards - -maintain and monitor use of PPE --lab aprons, lab coats, made from polyethylene or nitrile for aggressive and caustic materials --also use gloves and goggles

Question 38

Use of lab safety equipment

Answer 38

- -use safe chemical storage - -avoid taking out more materials than need - -first aid kit - -fire blankets: grease fire - -fire extinguisher - -glass disposal: appropriate bag/box, sealed, dispose - -above info does not apply to glassware with hazardous material - -eyewash: 15 minutes - -emergency shower